Faculty Bibliography

BACKGROUND: Retrospective studies have shown that nonspecific psychopathology and negative symptoms, including social isolation and academic dysfunction, tend to precede onset of psychosis. The present report describes the baseline psychopathology of subjects in the Hillside Recognition and Prevention (RAP) Program, and presents an operationalized classification algorithm for the prospective study of both positive and negative symptoms of clinical high-risk (CHR) for schizophrenia. METHODS: Eighty-two adolescent and young adult patients were characterized using semi-structured interviews of both a parent informant and the patient. The Scale of Prodromal Symptoms (SOPS) was utilized to derive a three-part classification scheme: CHR- subjects (n=20) were defined as having at least one attenuated negative symptom with no positive symptoms; CHR+ subjects (n=42) were defined as having one or more attenuated positive symptoms without psychosis; schizophrenia-like psychosis (SLP) subjects (n=20) were defined as having a psychotic symptom, but without meeting criterion A, B, or C of DSM-IV schizophrenia. RESULTS: Social isolation was the most common presenting symptom. The three RAP subgroups did not significantly differ in levels of attenuated negative and disorganized symptoms, despite the fact that these were not required for inclusion in the CHR+ and SLP groups. Common co-morbid diagnoses included major depression, attention deficit hyperactivity disorder, avoidant personality disorder, and Cluster A personality disorders. CONCLUSIONS: Negative symptoms and other nonspecific behavioral abnormalities represent clinically important phenomena in prodromal patients, and may provide insight into pathophysiologic mechanisms in schizophrenia and possible preventive interventions.

BACKGROUND: Neuropsychological research on children with bipolar disorder (BPD) is scarce. Here, we examine reward-related behaviors in children with BPD using a Wheel of Fortune task in which subjects could win or lose money depending on their decisions. The intent of this work was to investigate performance differences between BPD and healthy children on a task that could be used in an fMRI environment to inform the neural substrates of reward processes in BPD. This study has no direct clinical implications. We hypothesized that relative to healthy children, children with BPD would select risky options more frequently, be less confident in a favorable outcome, and report stronger emotional responses to outcomes. METHODS: Forty-four children (22 BPD; 22 control) were compared on (i) decision-making with varying levels of risk, (ii) level of confidence in favorable outcomes, and (iii) responses to feedback. The task included a win-no win version and a lose-no lose version. RESULTS: Patterns of selection did not differ between groups. In the lose-no lose task, BPD patients were less confident than controls in favorable outcomes. BPD patients expressed greater dissatisfaction than controls at not winning in win-no win, and greater satisfaction than controls at not losing in lose-no lose. LIMITATIONS: Limitations of this study included that the children with BPD were mostly in a depressed state, were medicated, and had co-morbid disorders. CONCLUSIONS: This is the first experimental study to examine associations between pediatric BPD and reward-related behaviors. Although we failed to detect abnormalities in risky decision-making in children with BPD, we found significant differences between groups in both confidence ratings and response to feedback, consistent with our predictions. Our ultimate goal is to use this task in the fMRI environment to gain a better understanding of the neural correlates of reward-related processes in pediatric BPD.

Biased attention to threat represents a key feature of anxiety disorders. This bias is altered by therapeutic or stressful experiences, suggesting that the bias is plastic. Charting on-line behavioral and neurophysiological changes in attention bias may generate insights on the nature of such plasticity. We used an attention-orientation task with threat cues to examine how healthy individuals alter their response over time to such cues. In Experiments 1 through 3, we established that healthy individuals demonstrate an increased attention bias away from threat over time. For Experiment 3, we used functional magnetic resonance imaging to determine the neural bases for this phenomenon. Gradually increasing attention bias away from threat is associated with increased activation in the occipitotemporal cortex. Examination of plasticity of attention bias with individuals at risk for anxiety disorders may reveal how threatening stimuli come to be categorized differently in this population over time.

We examined neural activations during decision-making using fMRI paired with the wheel of fortune task, a newly developed two-choice decision-making task with probabilistic monetary gains. In particular, we assessed the impact of high-reward/risk events relative to low-reward/risk events on neural activations during choice selection and during reward anticipation. Seventeen healthy adults completed the study. We found, in line with predictions, that (i) the selection phase predominantly recruited regions involved in visuo-spatial attention (occipito-parietal pathway), conflict (anterior cingulate), manipulation of quantities (parietal cortex), and preparation for action (premotor area), whereas the anticipation phase prominently recruited regions engaged in reward processes (ventral striatum); and (ii) high-reward/risk conditions relative to low-reward/risk conditions were associated with a greater neural response in ventral striatum during selection, though not during anticipation. Following an a priori ROI analysis focused on orbitofrontal cortex, we observed orbitofrontal cortex activation (BA 11 and 47) during selection (particularly to high-risk/reward options), and to a more limited degree, during anticipation. These findings support the notion that (1) distinct, although overlapping, pathways subserve the processes of selection and anticipation in a two-choice task of probabilistic monetary reward; (2) taking a risk and awaiting the consequence of a risky decision seem to affect neural activity differently in selection and anticipation; and thus (3) common structures, including the ventral striatum, are modulated differently by risk/reward during selection and anticipation.

BACKGROUND: Previous studies found few abnormalities in hypothalamic-pituitary-adrenal (HPA) axis function in prepubertal children with anxiety or depressive disorders. In this study, we combined data from two independent, consecutive studies to achieve a larger sample size. Our goal was to identify potential alterations in the circadian pattern of cortisol secretion in anxious or depressed children. METHODS: A total of 124 prepubertal subjects from two independent samples (76 with major depressive disorder, 31 with anxiety disorders, and 17 healthy control subjects) were studied. Blood samples collected for cortisol at hourly intervals over a 24-hour period were examined. Analyses were performed aligning cortisol samples by clock-time. Additional analyses aligning samples by sleep-onset time were performed with a subsample of subjects. RESULTS: In the combined sample, significant findings emerged that were previously undetected. Anxious children exhibited significantly lower nighttime cortisol levels and an initially sluggish rise in cortisol during the nighttime when compared with depressed and healthy control children. In contrast, depressed children did not show a clear-cut pattern of differences compared with healthy control children. CONCLUSIONS: Anxious children seem to exhibit an altered pattern of nighttime cortisol secretion, with an initially sluggish or delayed nocturnal rise before reaching similar peak levels of cortisol near the time of awakening. These findings suggest subtle alterations in HPA axis function in prepubertal children with anxiety disorders.

This chapter introduces three papers that summarize research findings in clinical and basic neuroscience. They integrate prior research on clinical aspects of developmental psychopathology, basic research on brain development in nonhuman primates, and neuroimaging research on both normal and abnormal human development. From the clinical perspective these papers call attention to the unique relationship between adolescence and psychopathology. From the basic science perspective they call attention to the sequence of events that culminates in a fully mature central nervous system.

BACKGROUND: Context conditioning has been suggested to model clinical anxiety, but context, as manipulated in animal models, has not been translated to human studies. A virtual environment might prove to be the ideal tool for innovative experimental paradigms to study explicitly cued fear and contextual anxiety in humans. METHODS: Subjects were guided through a virtual environment that consisted of two rooms connected by a street scene. In each of the rooms, a blue and a yellow panel on a wall served as explicit conditioned stimuli (CS). The panels were displayed several times. One of the panels (CS+) was associated with a shock in one of the rooms (shock room). No shock was administered in the other room (safe room). Acoustic startle stimuli were administered in the presence and in the absence of the panels to assess explicit cued conditioning to the CS and context conditioning to the rooms, respectively. RESULTS: Startle was potentiated by the CS+ in both rooms, which suggests generalization of fear across contexts. After acquisition, startle was potentiated in the shock room, compared with the safe room, in the absence of the CS+. CONCLUSIONS: These results support the future use of virtual reality to design new conditioning experiments to study both fear and anxiety.

BACKGROUND: Females appear to be more sensitive and responsive to social cues, including threat signals, than are males. Recent theoretical models suggest that developmental changes in brain functioning play important roles in the emergence of such gender differences. METHODS: We used functional magnetic resonance imaging to examine developmental and gender differences in activation of neural structures thought to mediate attention to emotional faces depicting varying degrees of threat. Analyses focused on the orbitofrontal cortex, amygdala, and anterior cingulate cortex during the evaluation of threat conveyed by faces. Healthy adolescents (n = 17; 53% male) and adults (n = 17; 53% male) were scanned while they rated how threatening pictures of neutral and emotional (angry, fearful, or happy) faces appeared. RESULTS: Results indicate significant interactions among age, gender, and face type for activation during explicit threat monitoring. In particular, adult women activated orbitofrontal cortex and amygdala selectively to unambiguous threat (angry) cues, while adult men showed a less discriminating pattern of activation. No gender differences were evident for adolescents, who as a group resembled adult males. CONCLUSIONS: These findings suggest that there are gender differences in patterns of neural responses to emotional faces that are not fully apparent until adulthood.